title: Cortico-striatal oxidative status, dopamine turnover and relation with stereotypy in the deer mouse.
abstract: The deer mouse presents with spontaneous stereotypic movements that resemble the repetitive behaviours of obsessive-compulsive disorder (OCD), and demonstrates a selective response to serotonin reuptake inhibitors. OCD has been linked to altered redox status and since increased dopamine signalling can promote stereotypies as well as oxidative stress, we investigated whether the severity of deer mouse stereotypy may be associated with altered dopamine turnover and cortico-striatal redox status. Deer mice were separated into high (HSB), low (LSB) and non-stereotypy (NS) groups. Frontal cortical and striatal dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), as well as superoxide dismutase (SOD) activity, reduced (GSH) and oxidised (GSSG) glutathione and glutathione redox index, were analysed as markers for regional dopamine turnover and oxidative stress, respectively. Dopamine and its metabolites and SOD activity did not differ across the stereotypy groups. Significantly reduced GSH and GSSG and increased glutathione redox index were only observed in the frontal cortex of HSB animals. Frontal cortical GSH and GSSG were inversely correlated while glutathione redox index was positively correlated with stereotypy. Deer mouse stereotypy is thus characterised by a deficient glutathione system in the frontal cortex but not striatum, and provides a therapeutic rationale for using glutathione-active antioxidants in OCD. The evidence for a primary frontal lesion has importance for future OCD research.
authors.affiliation: Division of Pharmacology, Unit for Drug Research and Development, School of Pharmacy, North-West University (Potchefstroom Campus), Hofman street, Potchefstroom, 2520, South Africa.
authors.forename: Marianne
authors.initials: M
authors.lastname: Güldenpfennig
authors.forename: De Wet
authors.initials: de W
authors.lastname: Wolmarans
authors.forename: Jan L
authors.initials: JL
authors.lastname: du Preez
authors.forename: Dan J
authors.initials: DJ
authors.lastname: Stein
authors.forename: Brian H
authors.initials: BH
authors.lastname: Harvey
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D006719:Homovanillic Acid / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D010088:Oxidoreductases / Q000378:metabolism; D010542:Peromyscus / Q000378:metabolism / Q000502:physiology; D012044:Regression Analysis; D013239:Stereotyped Behavior / Q000502:physiology*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D015102:3,4-Dihydroxyphenylacetic Acid; D010088:Oxidoreductases; D013482:Superoxide Dismutase; C020667:glutathione oxidase; D005978:Glutathione; D004298:Dopamine; D006719:Homovanillic Acid